Metabolic correlates of the effects of 2-deoxy-D-glucose on meal size and post-meal satiety in rats

The effects of 2-deoxy-D-glucose (2-DG) (250 mg/kg) combined with 0 to 6 hours of food deprivation on the size of the first meal and the first post-meal interval have been studied in rats and compared for the two parts of the diurnal cycle. The observed changes in meal patterns have been correlated to plasma glucose (PG) and plasma free fatty acid (PFFA) levels determined 30 min after the first meal. It was shown that, compared to saline, 2-DG reduced the size of the first meal and did not change the post-meal interval at night, whereas during the day 2-DG reduced the latency to eat and the meal-to-meal interval without changing the meal size. At night, the reduction of the first meal was associated with the 2-DG induced high levels of PG and PFFA observed after the meal or in the absence of food. During the day, the acceleration of meal onsets by 2-DG was associated with a higher PG and lower PFFA levels 30 min after the meal than at the corresponding time at night. The results are discussed in terms of a dual and antagonistic action of 2-DG on feeding.